#include <stdio.h>
#include <stdlib.h>

void fun(void);
int main(int argc, char *argv[]) {
  /* 函数原型
   */
  fun();
  int a = 10;
  int b = a;
  printf("%d\n", a);
  b = 20;
  printf("%d\n", b);
  int arr[5] = {1, 2, 3, 4, 5};
  int *arr2;
  arr2 = arr;
  for (int i = 0; i < 5; i++) {
    printf("%d\t", arr[i]);
  }
  printf("\n");
  arr2[0] = 100;
  for (int i = 0; i < 5; i++) {
    printf("%d\t", arr[i]);
  }
  printf("\n");
  int n = 100;
  int *p = &n;
  printf("%d\n", *p);
  int *q = p;
  *q = 70;
  printf("%d\n", *p);
  return EXIT_SUCCESS;
}

void fun(void) {}
